src/glx/dri_common.c - fp2-dev/platform/external/mesa3d - Gitiles

 /*
  * Copyright 1998-1999 Precision Insight, Inc., Cedar Park, Texas.
  * Copyright © 2008 Red Hat, Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Soft-
  * ware"), to deal in the Software without restriction, including without
  * limitation the rights to use, copy, modify, merge, publish, distribute,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, provided that the above copyright
  * notice(s) and this permission notice appear in all copies of the Soft-
  * ware and that both the above copyright notice(s) and this permission
  * notice appear in supporting documentation.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
  * ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY
  * RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN
  * THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSE-
  * QUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFOR-
  * MANCE OF THIS SOFTWARE.
  *
  * Except as contained in this notice, the name of a copyright holder shall
  * not be used in advertising or otherwise to promote the sale, use or
  * other dealings in this Software without prior written authorization of
  * the copyright holder.
  *
  * Authors:
  *   Kevin E. Martin <kevin@precisioninsight.com>
  *   Brian Paul <brian@precisioninsight.com>
  *   Kristian Høgsberg (krh@redhat.com)
  */

 #ifdef GLX_DIRECT_RENDERING

 #include <unistd.h>
 #include <dlfcn.h>
 #include <stdarg.h>
 #include "glxclient.h"
 #include "glcontextmodes.h"
 #include "dri_common.h"

 #ifndef RTLD_NOW
 #define RTLD_NOW 0
 #endif
 #ifndef RTLD_GLOBAL
 #define RTLD_GLOBAL 0
 #endif

 _X_HIDDEN void
 InfoMessageF(const char *f, ...)
 {
    va_list args;
    const char *env;

    if ((env = getenv("LIBGL_DEBUG")) && strstr(env, "verbose")) {
       fprintf(stderr, "libGL: ");
       va_start(args, f);
       vfprintf(stderr, f, args);
       va_end(args);
    }
 }

 /**
  * Print error to stderr, unless LIBGL_DEBUG=="quiet".
  */
 _X_HIDDEN void
 ErrorMessageF(const char *f, ...)
 {
    va_list args;
    const char *env;

    if ((env = getenv("LIBGL_DEBUG")) && !strstr(env, "quiet")) {
       fprintf(stderr, "libGL error: ");
       va_start(args, f);
       vfprintf(stderr, f, args);
       va_end(args);
    }
 }

 #ifndef DEFAULT_DRIVER_DIR
 /* this is normally defined in Mesa/configs/default with DRI_DRIVER_SEARCH_PATH */
 #define DEFAULT_DRIVER_DIR "/usr/local/lib/dri"
 #endif

 /**
  * Try to \c dlopen the named driver.
  *
  * This function adds the "_dri.so" suffix to the driver name and searches the
  * directories specified by the \c LIBGL_DRIVERS_PATH environment variable in
  * order to find the driver.
  *
  * \param driverName - a name like "tdfx", "i810", "mga", etc.
  *
  * \returns
  * A handle from \c dlopen, or \c NULL if driver file not found.
  */
 _X_HIDDEN void *
 driOpenDriver(const char *driverName)
 {
    void *glhandle, *handle;
    const char *libPaths, *p, *next;
    char realDriverName[200];
    int len;

    /* Attempt to make sure libGL symbols will be visible to the driver */
    glhandle = dlopen("libGL.so.1", RTLD_NOW | RTLD_GLOBAL);

    libPaths = NULL;
    if (geteuid() == getuid()) {
       /* don't allow setuid apps to use LIBGL_DRIVERS_PATH */
       libPaths = getenv("LIBGL_DRIVERS_PATH");
       if (!libPaths)
          libPaths = getenv("LIBGL_DRIVERS_DIR");        /* deprecated */
    }
    if (libPaths == NULL)
       libPaths = DEFAULT_DRIVER_DIR;

    handle = NULL;
    for (p = libPaths; *p; p = next) {
       next = strchr(p, ':');
       if (next == NULL) {
          len = strlen(p);
          next = p + len;
       }
       else {
          len = next - p;
          next++;
       }

 #ifdef GLX_USE_TLS
       snprintf(realDriverName, sizeof realDriverName,
                "%.*s/tls/%s_dri.so", len, p, driverName);
       InfoMessageF("OpenDriver: trying %s\n", realDriverName);
       handle = dlopen(realDriverName, RTLD_NOW | RTLD_GLOBAL);
 #endif

       if (handle == NULL) {
          snprintf(realDriverName, sizeof realDriverName,
                   "%.*s/%s_dri.so", len, p, driverName);
          InfoMessageF("OpenDriver: trying %s\n", realDriverName);
          handle = dlopen(realDriverName, RTLD_NOW | RTLD_GLOBAL);
       }

       if (handle != NULL)
          break;
       else
          ErrorMessageF("dlopen %s failed (%s)\n", realDriverName, dlerror());
    }

    if (!handle)
       ErrorMessageF("unable to load driver: %s_dri.so\n", driverName);

    if (glhandle)
       dlclose(glhandle);

    return handle;
 }

 _X_HIDDEN const __DRIsystemTimeExtension systemTimeExtension = {
    {__DRI_SYSTEM_TIME, __DRI_SYSTEM_TIME_VERSION},
    __glXGetUST,
    __driGetMscRateOML
 };

 #define __ATTRIB(attrib, field) \
     { attrib, offsetof(__GLcontextModes, field) }

 static const struct
 {
    unsigned int attrib, offset;
 } attribMap[] = {
    __ATTRIB(__DRI_ATTRIB_BUFFER_SIZE, rgbBits),
       __ATTRIB(__DRI_ATTRIB_LEVEL, level),
       __ATTRIB(__DRI_ATTRIB_RED_SIZE, redBits),
       __ATTRIB(__DRI_ATTRIB_GREEN_SIZE, greenBits),
       __ATTRIB(__DRI_ATTRIB_BLUE_SIZE, blueBits),
       __ATTRIB(__DRI_ATTRIB_ALPHA_SIZE, alphaBits),
       __ATTRIB(__DRI_ATTRIB_DEPTH_SIZE, depthBits),
       __ATTRIB(__DRI_ATTRIB_STENCIL_SIZE, stencilBits),
       __ATTRIB(__DRI_ATTRIB_ACCUM_RED_SIZE, accumRedBits),
       __ATTRIB(__DRI_ATTRIB_ACCUM_GREEN_SIZE, accumGreenBits),
       __ATTRIB(__DRI_ATTRIB_ACCUM_BLUE_SIZE, accumBlueBits),
       __ATTRIB(__DRI_ATTRIB_ACCUM_ALPHA_SIZE, accumAlphaBits),
       __ATTRIB(__DRI_ATTRIB_SAMPLE_BUFFERS, sampleBuffers),
       __ATTRIB(__DRI_ATTRIB_SAMPLES, samples),
       __ATTRIB(__DRI_ATTRIB_DOUBLE_BUFFER, doubleBufferMode),
       __ATTRIB(__DRI_ATTRIB_STEREO, stereoMode),
       __ATTRIB(__DRI_ATTRIB_AUX_BUFFERS, numAuxBuffers),
 #if 0
       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_TYPE, transparentPixel),
       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_INDEX_VALUE, transparentIndex),
       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_RED_VALUE, transparentRed),
       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_GREEN_VALUE, transparentGreen),
       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_BLUE_VALUE, transparentBlue),
       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_ALPHA_VALUE, transparentAlpha),
       __ATTRIB(__DRI_ATTRIB_RED_MASK, redMask),
       __ATTRIB(__DRI_ATTRIB_GREEN_MASK, greenMask),
       __ATTRIB(__DRI_ATTRIB_BLUE_MASK, blueMask),
       __ATTRIB(__DRI_ATTRIB_ALPHA_MASK, alphaMask),
 #endif
       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_WIDTH, maxPbufferWidth),
       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_HEIGHT, maxPbufferHeight),
       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_PIXELS, maxPbufferPixels),
       __ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_WIDTH, optimalPbufferWidth),
       __ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_HEIGHT, optimalPbufferHeight),
 #if 0
       __ATTRIB(__DRI_ATTRIB_SWAP_METHOD, swapMethod),
 #endif
 __ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGB, bindToTextureRgb),
       __ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGBA, bindToTextureRgba),
       __ATTRIB(__DRI_ATTRIB_BIND_TO_MIPMAP_TEXTURE,
                      bindToMipmapTexture),
       __ATTRIB(__DRI_ATTRIB_YINVERTED, yInverted),};

 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))

 static int
 scalarEqual(__GLcontextModes * mode, unsigned int attrib, unsigned int value)
 {
    unsigned int glxValue;
    int i;

    for (i = 0; i < ARRAY_SIZE(attribMap); i++)
       if (attribMap[i].attrib == attrib) {
          glxValue = *(unsigned int *) ((char *) mode + attribMap[i].offset);
          return glxValue == GLX_DONT_CARE || glxValue == value;
       }

    return GL_TRUE;              /* Is a non-existing attribute equal to value? */
 }

 static int
 driConfigEqual(const __DRIcoreExtension * core,
                __GLcontextModes * modes, const __DRIconfig * driConfig)
 {
    unsigned int attrib, value, glxValue;
    int i;

    i = 0;
    while (core->indexConfigAttrib(driConfig, i++, &attrib, &value)) {
       switch (attrib) {
       case __DRI_ATTRIB_RENDER_TYPE:
          glxValue = 0;
          if (value & __DRI_ATTRIB_RGBA_BIT) {
             glxValue |= GLX_RGBA_BIT;
          }
          else if (value & __DRI_ATTRIB_COLOR_INDEX_BIT) {
             glxValue |= GLX_COLOR_INDEX_BIT;
          }
          if (glxValue != modes->renderType)
             return GL_FALSE;
          break;

       case __DRI_ATTRIB_CONFIG_CAVEAT:
          if (value & __DRI_ATTRIB_NON_CONFORMANT_CONFIG)
             glxValue = GLX_NON_CONFORMANT_CONFIG;
          else if (value & __DRI_ATTRIB_SLOW_BIT)
             glxValue = GLX_SLOW_CONFIG;
          else
             glxValue = GLX_NONE;
          if (glxValue != modes->visualRating)
             return GL_FALSE;
          break;

       case __DRI_ATTRIB_BIND_TO_TEXTURE_TARGETS:
          glxValue = 0;
          if (value & __DRI_ATTRIB_TEXTURE_1D_BIT)
             glxValue |= GLX_TEXTURE_1D_BIT_EXT;
          if (value & __DRI_ATTRIB_TEXTURE_2D_BIT)
             glxValue |= GLX_TEXTURE_2D_BIT_EXT;
          if (value & __DRI_ATTRIB_TEXTURE_RECTANGLE_BIT)
             glxValue |= GLX_TEXTURE_RECTANGLE_BIT_EXT;
          if (modes->bindToTextureTargets != GLX_DONT_CARE &&
              glxValue != modes->bindToTextureTargets)
             return GL_FALSE;
          break;

       default:
          if (!scalarEqual(modes, attrib, value))
             return GL_FALSE;
       }
    }

    return GL_TRUE;
 }

 static __GLcontextModes *
 createDriMode(const __DRIcoreExtension * core,
               __GLcontextModes * modes, const __DRIconfig ** driConfigs)
 {
    __GLXDRIconfigPrivate *config;
    int i;

    for (i = 0; driConfigs[i]; i++) {
       if (driConfigEqual(core, modes, driConfigs[i]))
          break;
    }

    if (driConfigs[i] == NULL)
       return NULL;

    config = Xmalloc(sizeof *config);
    if (config == NULL)
       return NULL;

    config->modes = *modes;
    config->driConfig = driConfigs[i];

    return &config->modes;
 }

 _X_HIDDEN __GLcontextModes *
 driConvertConfigs(const __DRIcoreExtension * core,
                   __GLcontextModes * modes, const __DRIconfig ** configs)
 {
    __GLcontextModes head, *tail, *m;

    tail = &head;
    head.next = NULL;
    for (m = modes; m; m = m->next) {
       tail->next = createDriMode(core, m, configs);
       if (tail->next == NULL) {
          /* no matching dri config for m */
          continue;
       }


       tail = tail->next;
    }

    _gl_context_modes_destroy(modes);

    return head.next;
 }

 /* Bind DRI1 specific extensions */
 _X_HIDDEN void
 driBindExtensions(__GLXscreenConfigs *psc)
 {
    const __DRIextension **extensions;
    int i;

    extensions = psc->core->getExtensions(psc->__driScreen);

    for (i = 0; extensions[i]; i++) {
 #ifdef __DRI_SWAP_CONTROL
       /* No DRI2 support for swap_control at the moment, since SwapBuffers
        * is done by the X server */
       if (strcmp(extensions[i]->name, __DRI_SWAP_CONTROL) == 0) {
 	 psc->swapControl = (__DRIswapControlExtension *) extensions[i];
 	 __glXEnableDirectExtension(psc, "GLX_SGI_swap_control");
 	 __glXEnableDirectExtension(psc, "GLX_MESA_swap_control");
       }
 #endif

 #ifdef __DRI_MEDIA_STREAM_COUNTER
       if (strcmp(extensions[i]->name, __DRI_MEDIA_STREAM_COUNTER) == 0) {
          psc->msc = (__DRImediaStreamCounterExtension *) extensions[i];
          __glXEnableDirectExtension(psc, "GLX_SGI_video_sync");
       }
 #endif

 #ifdef __DRI_SWAP_BUFFER_COUNTER
       /* No driver supports this at this time and the extension is
        * not defined in dri_interface.h.  Will enable
        * GLX_OML_sync_control if implemented. */
 #endif

       /* Ignore unknown extensions */
    }
 }

 /* Bind DRI2 specific extensions */
 _X_HIDDEN void
 dri2BindExtensions(__GLXscreenConfigs *psc)
 {
    const __DRIextension **extensions;
    int i;

    extensions = psc->core->getExtensions(psc->__driScreen);

    for (i = 0; extensions[i]; i++) {
 #ifdef __DRI_TEX_BUFFER
       if ((strcmp(extensions[i]->name, __DRI_TEX_BUFFER) == 0)) {
 	 psc->texBuffer = (__DRItexBufferExtension *) extensions[i];
 	 __glXEnableDirectExtension(psc, "GLX_EXT_texture_from_pixmap");
       }
 #endif

       __glXEnableDirectExtension(psc, "GLX_SGI_video_sync");
       __glXEnableDirectExtension(psc, "GLX_SGI_swap_control");
       __glXEnableDirectExtension(psc, "GLX_MESA_swap_control");

       /* FIXME: if DRI2 version supports it... */
       __glXEnableDirectExtension(psc, "INTEL_swap_event");

 #ifdef __DRI2_FLUSH
       if ((strcmp(extensions[i]->name, __DRI2_FLUSH) == 0)) {
 	 psc->f = (__DRI2flushExtension *) extensions[i];
 	 /* internal driver extension, no GL extension exposed */
       }
 #endif
    }
 }

 /* Bind extensions common to DRI1 and DRI2 */
 _X_HIDDEN void
 driBindCommonExtensions(__GLXscreenConfigs *psc)
 {
    const __DRIextension **extensions;
    int i;

    extensions = psc->core->getExtensions(psc->__driScreen);

    for (i = 0; extensions[i]; i++) {
 #ifdef __DRI_COPY_SUB_BUFFER
       if (strcmp(extensions[i]->name, __DRI_COPY_SUB_BUFFER) == 0) {
 	 psc->driCopySubBuffer = (__DRIcopySubBufferExtension *) extensions[i];
 	 __glXEnableDirectExtension(psc, "GLX_MESA_copy_sub_buffer");
       }
 #endif

 #ifdef __DRI_ALLOCATE
       if (strcmp(extensions[i]->name, __DRI_ALLOCATE) == 0) {
 	 psc->allocate = (__DRIallocateExtension *) extensions[i];
 	 __glXEnableDirectExtension(psc, "GLX_MESA_allocate_memory");
       }
 #endif

 #ifdef __DRI_FRAME_TRACKING
       if (strcmp(extensions[i]->name, __DRI_FRAME_TRACKING) == 0) {
 	 psc->frameTracking = (__DRIframeTrackingExtension *) extensions[i];
 	 __glXEnableDirectExtension(psc, "GLX_MESA_swap_frame_usage");
       }
 #endif

 #ifdef __DRI_READ_DRAWABLE
       if (strcmp(extensions[i]->name, __DRI_READ_DRAWABLE) == 0) {
 	 __glXEnableDirectExtension(psc, "GLX_SGI_make_current_read");
       }
 #endif

       /* Ignore unknown extensions */
    }
 }

 #endif /* GLX_DIRECT_RENDERING */
	/*
	* Copyright 1998-1999 Precision Insight, Inc., Cedar Park, Texas.
	* Copyright © 2008 Red Hat, Inc.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Soft-
	* ware"), to deal in the Software without restriction, including without
	* limitation the rights to use, copy, modify, merge, publish, distribute,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, provided that the above copyright
	* notice(s) and this permission notice appear in all copies of the Soft-
	* ware and that both the above copyright notice(s) and this permission
	* notice appear in supporting documentation.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
	* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
	* ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY
	* RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN
	* THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSE-
	* QUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
	* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
	* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFOR-
	* MANCE OF THIS SOFTWARE.
	*
	* Except as contained in this notice, the name of a copyright holder shall
	* not be used in advertising or otherwise to promote the sale, use or
	* other dealings in this Software without prior written authorization of
	* the copyright holder.
	*
	* Authors:
	* Kevin E. Martin <kevin@precisioninsight.com>
	* Brian Paul <brian@precisioninsight.com>
	* Kristian Høgsberg (krh@redhat.com)
	*/

	#ifdef GLX_DIRECT_RENDERING

	#include <unistd.h>
	#include <dlfcn.h>
	#include <stdarg.h>
	#include "glxclient.h"
	#include "glcontextmodes.h"
	#include "dri_common.h"

	#ifndef RTLD_NOW
	#define RTLD_NOW 0
	#endif
	#ifndef RTLD_GLOBAL
	#define RTLD_GLOBAL 0
	#endif

	_X_HIDDEN void
	InfoMessageF(const char *f, ...)
	{
	va_list args;
	const char *env;

	if ((env = getenv("LIBGL_DEBUG")) && strstr(env, "verbose")) {
	fprintf(stderr, "libGL: ");
	va_start(args, f);
	vfprintf(stderr, f, args);
	va_end(args);
	}
	}

	/**
	* Print error to stderr, unless LIBGL_DEBUG=="quiet".
	*/
	_X_HIDDEN void
	ErrorMessageF(const char *f, ...)
	{
	va_list args;
	const char *env;

	if ((env = getenv("LIBGL_DEBUG")) && !strstr(env, "quiet")) {
	fprintf(stderr, "libGL error: ");
	va_start(args, f);
	vfprintf(stderr, f, args);
	va_end(args);
	}
	}

	#ifndef DEFAULT_DRIVER_DIR
	/* this is normally defined in Mesa/configs/default with DRI_DRIVER_SEARCH_PATH */
	#define DEFAULT_DRIVER_DIR "/usr/local/lib/dri"
	#endif

	/**
	* Try to \c dlopen the named driver.
	*
	* This function adds the "_dri.so" suffix to the driver name and searches the
	* directories specified by the \c LIBGL_DRIVERS_PATH environment variable in
	* order to find the driver.
	*
	* \param driverName - a name like "tdfx", "i810", "mga", etc.
	*
	* \returns
	* A handle from \c dlopen, or \c NULL if driver file not found.
	*/
	_X_HIDDEN void *
	driOpenDriver(const char *driverName)
	{
	void glhandle, handle;
	const char libPaths, p, *next;
	char realDriverName[200];
	int len;

	/* Attempt to make sure libGL symbols will be visible to the driver */
	glhandle = dlopen("libGL.so.1", RTLD_NOW \| RTLD_GLOBAL);

	libPaths = NULL;
	if (geteuid() == getuid()) {
	/* don't allow setuid apps to use LIBGL_DRIVERS_PATH */
	libPaths = getenv("LIBGL_DRIVERS_PATH");
	if (!libPaths)
	libPaths = getenv("LIBGL_DRIVERS_DIR"); /* deprecated */
	}
	if (libPaths == NULL)
	libPaths = DEFAULT_DRIVER_DIR;

	handle = NULL;
	for (p = libPaths; *p; p = next) {
	next = strchr(p, ':');
	if (next == NULL) {
	len = strlen(p);
	next = p + len;
	}
	else {
	len = next - p;
	next++;
	}

	#ifdef GLX_USE_TLS
	snprintf(realDriverName, sizeof realDriverName,
	"%.*s/tls/%s_dri.so", len, p, driverName);
	InfoMessageF("OpenDriver: trying %s\n", realDriverName);
	handle = dlopen(realDriverName, RTLD_NOW \| RTLD_GLOBAL);
	#endif

	if (handle == NULL) {
	snprintf(realDriverName, sizeof realDriverName,
	"%.*s/%s_dri.so", len, p, driverName);
	InfoMessageF("OpenDriver: trying %s\n", realDriverName);
	handle = dlopen(realDriverName, RTLD_NOW \| RTLD_GLOBAL);
	}

	if (handle != NULL)
	break;
	else
	ErrorMessageF("dlopen %s failed (%s)\n", realDriverName, dlerror());
	}

	if (!handle)
	ErrorMessageF("unable to load driver: %s_dri.so\n", driverName);

	if (glhandle)
	dlclose(glhandle);

	return handle;
	}

	_X_HIDDEN const __DRIsystemTimeExtension systemTimeExtension = {
	{__DRI_SYSTEM_TIME, __DRI_SYSTEM_TIME_VERSION},
	__glXGetUST,
	__driGetMscRateOML
	};

	#define __ATTRIB(attrib, field) \
	{ attrib, offsetof(__GLcontextModes, field) }

	static const struct
	{
	unsigned int attrib, offset;
	} attribMap[] = {
	__ATTRIB(__DRI_ATTRIB_BUFFER_SIZE, rgbBits),
	__ATTRIB(__DRI_ATTRIB_LEVEL, level),
	__ATTRIB(__DRI_ATTRIB_RED_SIZE, redBits),
	__ATTRIB(__DRI_ATTRIB_GREEN_SIZE, greenBits),
	__ATTRIB(__DRI_ATTRIB_BLUE_SIZE, blueBits),
	__ATTRIB(__DRI_ATTRIB_ALPHA_SIZE, alphaBits),
	__ATTRIB(__DRI_ATTRIB_DEPTH_SIZE, depthBits),
	__ATTRIB(__DRI_ATTRIB_STENCIL_SIZE, stencilBits),
	__ATTRIB(__DRI_ATTRIB_ACCUM_RED_SIZE, accumRedBits),
	__ATTRIB(__DRI_ATTRIB_ACCUM_GREEN_SIZE, accumGreenBits),
	__ATTRIB(__DRI_ATTRIB_ACCUM_BLUE_SIZE, accumBlueBits),
	__ATTRIB(__DRI_ATTRIB_ACCUM_ALPHA_SIZE, accumAlphaBits),
	__ATTRIB(__DRI_ATTRIB_SAMPLE_BUFFERS, sampleBuffers),
	__ATTRIB(__DRI_ATTRIB_SAMPLES, samples),
	__ATTRIB(__DRI_ATTRIB_DOUBLE_BUFFER, doubleBufferMode),
	__ATTRIB(__DRI_ATTRIB_STEREO, stereoMode),
	__ATTRIB(__DRI_ATTRIB_AUX_BUFFERS, numAuxBuffers),
	#if 0
	__ATTRIB(__DRI_ATTRIB_TRANSPARENT_TYPE, transparentPixel),
	__ATTRIB(__DRI_ATTRIB_TRANSPARENT_INDEX_VALUE, transparentIndex),
	__ATTRIB(__DRI_ATTRIB_TRANSPARENT_RED_VALUE, transparentRed),
	__ATTRIB(__DRI_ATTRIB_TRANSPARENT_GREEN_VALUE, transparentGreen),
	__ATTRIB(__DRI_ATTRIB_TRANSPARENT_BLUE_VALUE, transparentBlue),
	__ATTRIB(__DRI_ATTRIB_TRANSPARENT_ALPHA_VALUE, transparentAlpha),
	__ATTRIB(__DRI_ATTRIB_RED_MASK, redMask),
	__ATTRIB(__DRI_ATTRIB_GREEN_MASK, greenMask),
	__ATTRIB(__DRI_ATTRIB_BLUE_MASK, blueMask),
	__ATTRIB(__DRI_ATTRIB_ALPHA_MASK, alphaMask),
	#endif
	__ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_WIDTH, maxPbufferWidth),
	__ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_HEIGHT, maxPbufferHeight),
	__ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_PIXELS, maxPbufferPixels),
	__ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_WIDTH, optimalPbufferWidth),
	__ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_HEIGHT, optimalPbufferHeight),
	#if 0
	__ATTRIB(__DRI_ATTRIB_SWAP_METHOD, swapMethod),
	#endif
	__ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGB, bindToTextureRgb),
	__ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGBA, bindToTextureRgba),
	__ATTRIB(__DRI_ATTRIB_BIND_TO_MIPMAP_TEXTURE,
	bindToMipmapTexture),
	__ATTRIB(__DRI_ATTRIB_YINVERTED, yInverted),};

	#define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))

	static int
	scalarEqual(__GLcontextModes * mode, unsigned int attrib, unsigned int value)
	{
	unsigned int glxValue;
	int i;

	for (i = 0; i < ARRAY_SIZE(attribMap); i++)
	if (attribMap[i].attrib == attrib) {
	glxValue = (unsigned int ) ((char *) mode + attribMap[i].offset);
	return glxValue == GLX_DONT_CARE \|\| glxValue == value;
	}

	return GL_TRUE; /* Is a non-existing attribute equal to value? */
	}

	static int
	driConfigEqual(const __DRIcoreExtension * core,
	__GLcontextModes * modes, const __DRIconfig * driConfig)
	{
	unsigned int attrib, value, glxValue;
	int i;

	i = 0;
	while (core->indexConfigAttrib(driConfig, i++, &attrib, &value)) {
	switch (attrib) {
	case __DRI_ATTRIB_RENDER_TYPE:
	glxValue = 0;
	if (value & __DRI_ATTRIB_RGBA_BIT) {
	glxValue \|= GLX_RGBA_BIT;
	}
	else if (value & __DRI_ATTRIB_COLOR_INDEX_BIT) {
	glxValue \|= GLX_COLOR_INDEX_BIT;
	}
	if (glxValue != modes->renderType)
	return GL_FALSE;
	break;

	case __DRI_ATTRIB_CONFIG_CAVEAT:
	if (value & __DRI_ATTRIB_NON_CONFORMANT_CONFIG)
	glxValue = GLX_NON_CONFORMANT_CONFIG;
	else if (value & __DRI_ATTRIB_SLOW_BIT)
	glxValue = GLX_SLOW_CONFIG;
	else
	glxValue = GLX_NONE;
	if (glxValue != modes->visualRating)
	return GL_FALSE;
	break;

	case __DRI_ATTRIB_BIND_TO_TEXTURE_TARGETS:
	glxValue = 0;
	if (value & __DRI_ATTRIB_TEXTURE_1D_BIT)
	glxValue \|= GLX_TEXTURE_1D_BIT_EXT;
	if (value & __DRI_ATTRIB_TEXTURE_2D_BIT)
	glxValue \|= GLX_TEXTURE_2D_BIT_EXT;
	if (value & __DRI_ATTRIB_TEXTURE_RECTANGLE_BIT)
	glxValue \|= GLX_TEXTURE_RECTANGLE_BIT_EXT;
	if (modes->bindToTextureTargets != GLX_DONT_CARE &&
	glxValue != modes->bindToTextureTargets)
	return GL_FALSE;
	break;

	default:
	if (!scalarEqual(modes, attrib, value))
	return GL_FALSE;
	}
	}

	return GL_TRUE;
	}

	static __GLcontextModes *
	createDriMode(const __DRIcoreExtension * core,
	__GLcontextModes * modes, const __DRIconfig ** driConfigs)
	{
	__GLXDRIconfigPrivate *config;
	int i;

	for (i = 0; driConfigs[i]; i++) {
	if (driConfigEqual(core, modes, driConfigs[i]))
	break;
	}

	if (driConfigs[i] == NULL)
	return NULL;

	config = Xmalloc(sizeof *config);
	if (config == NULL)
	return NULL;

	config->modes = *modes;
	config->driConfig = driConfigs[i];

	return &config->modes;
	}

	_X_HIDDEN __GLcontextModes *
	driConvertConfigs(const __DRIcoreExtension * core,
	__GLcontextModes * modes, const __DRIconfig ** configs)
	{
	__GLcontextModes head, tail, m;

	tail = &head;
	head.next = NULL;
	for (m = modes; m; m = m->next) {
	tail->next = createDriMode(core, m, configs);
	if (tail->next == NULL) {
	/* no matching dri config for m */
	continue;
	}


	tail = tail->next;
	}

	_gl_context_modes_destroy(modes);

	return head.next;
	}

	/* Bind DRI1 specific extensions */
	_X_HIDDEN void
	driBindExtensions(__GLXscreenConfigs *psc)
	{
	const __DRIextension **extensions;
	int i;

	extensions = psc->core->getExtensions(psc->__driScreen);

	for (i = 0; extensions[i]; i++) {
	#ifdef __DRI_SWAP_CONTROL
	/* No DRI2 support for swap_control at the moment, since SwapBuffers
	* is done by the X server */
	if (strcmp(extensions[i]->name, __DRI_SWAP_CONTROL) == 0) {
	psc->swapControl = (__DRIswapControlExtension *) extensions[i];
	__glXEnableDirectExtension(psc, "GLX_SGI_swap_control");
	__glXEnableDirectExtension(psc, "GLX_MESA_swap_control");
	}
	#endif

	#ifdef __DRI_MEDIA_STREAM_COUNTER
	if (strcmp(extensions[i]->name, __DRI_MEDIA_STREAM_COUNTER) == 0) {
	psc->msc = (__DRImediaStreamCounterExtension *) extensions[i];
	__glXEnableDirectExtension(psc, "GLX_SGI_video_sync");
	}
	#endif

	#ifdef __DRI_SWAP_BUFFER_COUNTER
	/* No driver supports this at this time and the extension is
	* not defined in dri_interface.h. Will enable
	* GLX_OML_sync_control if implemented. */
	#endif

	/* Ignore unknown extensions */
	}
	}

	/* Bind DRI2 specific extensions */
	_X_HIDDEN void
	dri2BindExtensions(__GLXscreenConfigs *psc)
	{
	const __DRIextension **extensions;
	int i;

	extensions = psc->core->getExtensions(psc->__driScreen);

	for (i = 0; extensions[i]; i++) {
	#ifdef __DRI_TEX_BUFFER
	if ((strcmp(extensions[i]->name, __DRI_TEX_BUFFER) == 0)) {
	psc->texBuffer = (__DRItexBufferExtension *) extensions[i];
	__glXEnableDirectExtension(psc, "GLX_EXT_texture_from_pixmap");
	}
	#endif

	__glXEnableDirectExtension(psc, "GLX_SGI_video_sync");
	__glXEnableDirectExtension(psc, "GLX_SGI_swap_control");
	__glXEnableDirectExtension(psc, "GLX_MESA_swap_control");

	/* FIXME: if DRI2 version supports it... */
	__glXEnableDirectExtension(psc, "INTEL_swap_event");

	#ifdef __DRI2_FLUSH
	if ((strcmp(extensions[i]->name, __DRI2_FLUSH) == 0)) {
	psc->f = (__DRI2flushExtension *) extensions[i];
	/* internal driver extension, no GL extension exposed */
	}
	#endif
	}
	}

	/* Bind extensions common to DRI1 and DRI2 */
	_X_HIDDEN void
	driBindCommonExtensions(__GLXscreenConfigs *psc)
	{
	const __DRIextension **extensions;
	int i;

	extensions = psc->core->getExtensions(psc->__driScreen);

	for (i = 0; extensions[i]; i++) {
	#ifdef __DRI_COPY_SUB_BUFFER
	if (strcmp(extensions[i]->name, __DRI_COPY_SUB_BUFFER) == 0) {
	psc->driCopySubBuffer = (__DRIcopySubBufferExtension *) extensions[i];
	__glXEnableDirectExtension(psc, "GLX_MESA_copy_sub_buffer");
	}
	#endif

	#ifdef __DRI_ALLOCATE
	if (strcmp(extensions[i]->name, __DRI_ALLOCATE) == 0) {
	psc->allocate = (__DRIallocateExtension *) extensions[i];
	__glXEnableDirectExtension(psc, "GLX_MESA_allocate_memory");
	}
	#endif

	#ifdef __DRI_FRAME_TRACKING
	if (strcmp(extensions[i]->name, __DRI_FRAME_TRACKING) == 0) {
	psc->frameTracking = (__DRIframeTrackingExtension *) extensions[i];
	__glXEnableDirectExtension(psc, "GLX_MESA_swap_frame_usage");
	}
	#endif

	#ifdef __DRI_READ_DRAWABLE
	if (strcmp(extensions[i]->name, __DRI_READ_DRAWABLE) == 0) {
	__glXEnableDirectExtension(psc, "GLX_SGI_make_current_read");
	}
	#endif

	/* Ignore unknown extensions */
	}
	}

	#endif /* GLX_DIRECT_RENDERING */